Production of Bio-MEG, Monoethylene Glycol

Monoethylene glycol (MEG) is a very important raw material largely used in packaging, antifreeze, and the manufacture of polyester fibers, polyethylene terephthalate plastics, and resins. The traditional method for MEG production relies on petroleum-based feedstocks as ethylene produced by steam cracking of hydrocarbons is the conventional starting material. Since the 1970’s, companies like Shell Oil Corporation and Coca-Cola have been developing technology to produce MEG via bio-based and renewable alternatives. This paper explores an alternative method to the industrial-scale production of MEG from glucose syrup. The proposed process utilizes 92,000 kg/hr of glucose syrup and a bi-catalyst system consisting of a 0.50wt% homogenous tungsten in water catalyst and a heterogeneous ruthenium catalyst on activated carbon. A CSTR and PFR reactor are used in series to produce 406 Kta of 99.8% pure MEG, which is separated by four distillation columns and a mass separating agent. The CSTR is operated at 220°C and 65 bar, while the PFR is operated at 260°C and 55 bar. The massive volume of water necessary for the homogeneous catalyst is removed from the process via a four stage multi-effect evaporator. Based on the current prices of the various feedstocks and products, including the side-products of propylene glycol and butylene glycol, an economic analysis predicted a negative IRR over 15 years, an ROI of -30.1% in year 3, and a NPV of -$527K. The economics are reflective of a 15% green premium added to the current industry price of MEG. Although this project does not meet the design constraints, which leads to the conclusion that with additional modifications and improvements in the design and an increase in the green premium, the project could be profitable in the future.